Focusing means for light projectors



Jan. 5 1926. 1,568,169

' S. L. LEBBY FOCUSING MEANS FOR LI GHT PRQ'J'ECTORS Filed Sept. 15, 1922 5 22 ferslkc 1, C5 3;

Patented Jan. 5, 1926.

UNITED, STATES iPATENTtOFFl'CE.

STATES LEE LEBBY, F CORNING, NEW YORK.

rocusme :aEANs FQR LIsn'r rnoanc'mons.

Application filed September 15, 1922 Seria1No.-588,402.

To all whom it. may concern .2

Be it knownthat I, Sums-LanflLnnnr,

a citizen of-the United States of America,

and a resident of Corning, New York, have invented. certain new and useful Improvements in Focusing -Means for Light Projectors, of whichflthe following is-a speci-- This inventiorris an'improvement-inf focusing means for light projectors.

The to prov de an improved means for support.-

ing and adjusting thelight source of a light projector,.ha ving the advantages of simplicity in design, economy in construction, ease in assembly and disasseinbly, and

accuracy and simplicity in operation.

These and further .objects of the inven-. tion will become more fully apparent as the description proceeds. j In the drawings forming a part of this application. I

Figure 1 is a front elevational view of a lamp equipped with the invention:

through.

Figure 2 is Figure 3 is a fragmentalperspective View of thelamp and lower portion of the focusing device. v

For' convenience of illustration, '1 have shown the invention as applied to a spot light of the type commonly used on auto mobiles.

In the drawings, 5 indicates the lampcasing, and 6 the refiector'i The latter is retained in place by'a ring 7 engaging its forward edge and afiixed to the interior of the casing. The particular type of reflector shown is ordinarily manufactured with a continuous beveled surface 8 just rearwardly of its forward edge. However, 'to' effect the operation of the 'invention the beveled surface need not be continuous, it

3 being suflicient if the portion opposite which (which is nearest the reflector) than at its outer end. Atits inner end the plate is cut awayas at 12 to form'spaced ears 1?), which engage between the beveled edge 8, and the rincipal object of the'inven'tion is a sectional view there-.

paratively large.

casing, and upon which the base plate will rock on an axis at rightangles' to the axis ofthe reflector, as, the plate is moved inwardly or outwardly during the focusing operation. Since the light source 11 is supported on theplate through the medium of the standard 10, pivotal movement of the .plate inwardly or outwardly with respect to the axis of the lamp, will effect a movement of the light source toward or away fromthe reflector.

Afscrewor threaded bolt 14 extends 'through an opening in the lamp casing 5, and through an opening in the base plate 9, "and on this screw is arranged a sprin which bears against the inner surface of the baseplat e, and the tension of which is adjusted by means of an adjusting nut 16 mounted on the inner end of the screw. The screw is preferably arranged between the standard 10-andthe inner end of the base plate, and isequi-distant from the ears 13,

so that the pressure exerted by the spring upon'the base plate will be evenly distributed between the two'lateral halves of the base plate. An adjusting screw 17 is threaded through the casing and bears at its inner end against the under side of the base plate, and preferably near the. outer endthereof beneath the. standard 10. The adjustingv screw is alined with respect to the spring 15, longitudinally of the base plate, and hence by reason of the even distribution of the pressure of the spring over the base base plate to rock laterally. The adjusting screw 17 is preferably provided with threads of such pitch that fine adjustment of the base: plate 9-, can be secured. .The adjustng screw operates upon. the plate in opposition to the spring 15, and thusthe ten- .sion of the spring will retain the plate in. adjusted position.

While the maximum field of adjustment of the base plate 9 is comparatively small, the movements of the plate will be amplified, by reason of the length'ofthe standard 10, so that the field of adjustment of the light source is com- The standard 10 is preferably made of a sheet of material doubled upon itself longitudinally,'and having its lower end split along the bend for a short distance, the sides of the standard being then out-turned to form flanges 18, which may be riveted plate, and the position of theadjusting screw, there will be no tendency for the or soldered, orfotherwise suitably secured to the base plate 9. The material forming the bend, for a suitable distance at the upper end of the standard, may be removed, and

the sides of the standard formed into a holder-19 in which a lamp socket 20 may be suitably mounted. From the contacts 21 of the socket, light wires may be led through the standard; i. e., between the lateral sides' 10 thereof, and in desirable manner conducted to the source of current. 'The holder 19 formed at the upper part of the standard is preferably arranged approximately in the axis of the reflector G, and the standard 10 5 is inclined vertically to the proper degree,

so that when the incandescent bulb 11 is placed in the socket, the filament of the bulb will be approximately in the focus of the reflector. In the particular type and size 0 of reflector used in this instance as an illus 25 source, and the desired position of thevlight 9' and source, will determine in various instances, the position to be given the standard 10. In some instances, it might be arranged at right angles to the plate in 7 others it might be inclined toward the rear of the lamp. 'By thus proportioning the parts so that the lamp when affixed in its-socket will be approximately adjusted, correct adjustment of the light 3 source, toward or away from the reflector can then be had by manipulating the adjusting screw 17. 7

The ring 7, which retains the reflector 6 in place is interrupted through that area which is occupied by thebase plate 9, so as to allow of the positioning of the pivotal ears 13 against the beveled face 8 of the reflector. 1

While the plate in the type illustrated is shown as placed on the bottom of the lamp casing, the standard extending upwardly, it will be understood that the plate .can be arranged at other points with respect to the circumference of the casing if so desired.

In assembling the device, the reflector 6 and retaining ring 7 having been secured in place in the lamp casing, the base platecarrying with it the standard and the light source, may be properly positioned in the casing. The screw 14 may be then inserted through the alined openings in the casing and the base plate, the spring 15 dropped in place upon the screw, and the adjusting screw 17 may be then turned into the casing, and the wires having been connected with the source of current, and the current switched on, the adjusting screw may be turned to give the desired initial adjustment to the light source, The cover glass 22 may then be mounted on the lamp.

I The adjustment secured by this deviceis longitudinal adjustment of the light source substantially axially with respect to the reflector. Such adjustment will secure the desired angle of beam divergence, ac-

cording to well known optical laws, The

lateral axial position of the light source relative to the reflector is approximately correct by reason of the positioning of the holder". '19 and its socket 20, and need not be changed. The longitudinal adjust: ment of the light source substantially along the axis, however, must be provided for in order to obtain the desired angle of-beam divergence.

Having thus described the invention what 4 is claimed.is,'

1. The combination with a projector, of a light source carrying plate mounted for pivotal movement about an axis, an adjustmg means operating against the plate in between the said beveled surface and said casing, a light source carried by the plate, and means for adjusting the plate, and re taiining it in adjusted position.

3. The combination with a projector casing and a reflector mounted therein, of a base plate having spaced pivotal ears engaging against the reflector and easing, resilient means pressing the plate in one direction, adjusting means adapted to move the plate against the pressure of said resilient means, and a light source supported by the plate.

4;. The combination with a projector casing, of a base plate, a light source-carrying standard mounted on the plate, spring means urging the plate against the casing, and an adjusting means operating against the plate in opposition to the spring means and to one side thereof, whereby the edge of the base plate on the other side of the spring from the adjusting means will form a bearing contact with the casing.

5. In a focusing means for light projectors, a base plate having spaced bearing cars. a light-supporting standard mounted on the base plate, spring means substan tially equidistant from the bearing ears, and bearing on one side of the plate, and adjusting means beyond the spring means with respect to the' bearing ears, and engaging the opposite side of the plate.

6. The combination with a projector casing and its light bulb, of means for supporting and focusing said bulb comprising a standard carrying said bulb at its upper end and having its lower end resiliently pivoted to the casing on an axis at right angles to the axis of. the projector, and screw means threaded through the bottom of the projector casing and acting against said standard at \a pivot.

7. The combination with a rojector cas- 10 ing, of a light carryingstan ard having a point remote from its base portion elongated in a direction parallel with the axis of the projector, and havremoved from its point of pivotal connec-' STATES LEE LEBBY. 

